What eats flatworms?

[Reef_Ready]

Not that I want to start another Flat worm exit thread (there are enough of them on RC), but I used it a couple of months ago. It worked for a while but now they are back with a vengence. I think it works better than anything else out there, but not 100% effective by a long shot. As Doug pointed out it didn't seem to have any ill effects on the live rock, coral or fish.